[Harry Axten] turned the diminutive Korg Monotron into a playable analog synthesizer, complete with a full-sized keyboard spanning two octaves and a MIDI interface.
Korg Introduced the Monotron analog mini-synthesizer back in 2010. They also dropped the schematics for the synth. Hackers wasted no time modifying and improving the Monotron. [Harry] incorporated several of these changes into his build. The Low-Frequency Oscillator (LFO) has been changed over to an envelope generator. The ribbon controller is gone, replaced with a CV/gate interface to sound notes.
The CV/gate interface, in turn, is connected to an ATMega328P which converts it to MIDI. MIDI data comes from one of two sources: A two-octave full-sized keyboard pulled from a scrapped MIDI controller or a MIDI connector at the back.
The user interface doesn’t stop with the keyboard. The low-cost pots on the original Monotron have been replaced with much higher quality parts on the front panel. The tuning pot is a 10-turn device, which allows for precision tuning. All the mods are mounted on a single board, which is connected to the original Monotron board.
The fruit of all hard work is an instrument that is a heck of a lot of fun to play. Check it out in the video below. Want more? You can read all about hacking about the Monotron’s bigger brother, the Monotribe.





Hamilton soon moved on to the SAGE program, writing software which would monitor radar data for incoming Russian bombers. Her work on SAGE put Margaret in the perfect position to jump to the new Apollo navigation software team.
Now that we’ve got you excited, let’s mention what the North Star is not — it’s not a consumer device. Leap Motion’s idea here was to create a platform for developing Augmented Reality experiences — the user interface and interaction aspects. To that end, they built the best head-mounted display they could on a budget. The company started with standard 5.5″ cell phone displays, which made for an incredibly high resolution but low framerate (50 Hz) device. It was also large and completely unpractical.